Electric Current (Encyclopedia of Science)
An electric current is usually thought of as a flow of electrons. When two ends of a battery are connected to each other by means of a metal wire, electrons flow out of one end (electrode or pole) of the battery, through the wire, and into the opposite end of the battery.
An electric current can also be thought of as a flow of positive "holes." A "hole" in this sense is a region of space where an electron might normally be found but does not exist. The absence of the electron's negative charge can be thought of as creating a positively charged hole.
In some cases, an electric current can also consist of a flow of positively charge particles known as cations. A cation is simply an atom or group of atoms carrying a positive charge.
The ampere (amp) is used to measure the amount of current flow. The unit was named for French mathematician and physicist André Marie Ampère (1775836), who founded the modern study of electric currents. The ampere is defined in terms of the number of electrons that pass any given point in some unit of time. Since electric charge is measured in coulombs, an exact definition for the ampere is the number of coulombs that pass a given point each second.
Characteristics of an electric current
Potential difference. In...
(The entire section is 1512 words.)
Want to Read More?
Subscribe now to read the rest of this article. Plus get complete access to 30,000+ study guides!